Run tests for several compiler versions

Fixed edge case for empty View

Fixed error check for old storyboard files

Fixed issue with previous commit

Changed the error checking logic so that macOs storyboards and Xibs d…

…o not bypass the check.

Improved error handling for cases when the file is completely empty

Fixed bug when dealing with errors

Added alpha property to all views

Fixed mapping issue in Label

Added support for very long string elements in TextView and Label